In image forming apparatuses such as a printer and a MFP (Multi Function Peripheral), for example, sheets having different characteristics such as recycled paper, a thick sheet, and a thin sheet are used.
Depending on a characteristic of a sheet in use, the density of a printed image, or the like, show-through in which a color material penetrating into a printing sheet can be visually recognized from the rear surface side of the printing sheet occurs. In some cases, the show-through deteriorates, in simplex printing, the appearance on the rear surface side and, in duplex printing, makes it difficult to read an image on the printed surface because the image overlaps a show-through image. In the simplex printing and the duplex printing, since the show-through involves a blur of the color material deterioration in an image quality on the printed surface is caused.